I have a dc arc welder 130 amp output is it possible to use this as a power supply for tig welding.If so what would it entail.
I have done a lot of DC TIG welding with stick machines. It will work fine on steel and stainless, but of course you would an AC high-frequency power source for aluminum.
You will need a cylinder of argon with a regulator, an argon hose, a "power-block" which goes between the argon hose and the hose/cable to the torch.
Hook your negative electrode to the power block and positive ground to the work piece and you will have a "scratch-start" TIG set-up. I've welded millions of dollars worth of stainless with a set-up just like that.
Please forgive my ignorance what is a power block
A power block is simply a piece of metal with lugs on it to electrically connect it to your negative post on the welder, and let you hook up a tig torch to it as well as your usual stinger or ground clamp.
Costs maybe 15 bucks- big chunk of bronze, usually.
The guys at the welding supply will know.
This setup, the one described above, with a regulator, argon tank, and a scratch start air cooled tig torch, will get you started tig welding, for about $250 plus an argon tank.
Scratch start works fine, you just foul your tungsten more often than you would with a fancy high frequency starter. Which means you get lots of practice sharpening tungstens. Its good for you, builds character.
The cheap (around $150) air cooled scratch start tig torch will have a knob right on the torch handle to turn on and off the argon flow. Argon is expensive, so you have to be good about learning to only turn it on when you are welding.
Depending on how much welding you do, how thick the material is, and what it is, the air cooled torch may get kinda hot sometimes- and you may have to take a break and let it cool down.
Next step up, in terms of price and convenience, is a water cooled torch- similar cost for the torch, but you need a $500 radiator to run anti-freeze thru it.
Then you could spend a bunch more, and buy an add on High Frequency unit- this allows you to start the arc much easier, without actually touching the tungsten to the base metal. It also would allow you to weld aluminum, if you had an AC power supply.
I have all of these things, and use them in various combinations, depending on the job.
A scratch start torch can plug right into a rented gas drive Trailblazer, and I can tig weld on site with a minimum of fuss. Or down a hole, or up a ladder.
Other times, I drag out the radiator, foot pedal, and high freq unit, and can do very controlled precision tig welding anywhere I want- did a job a couple years ago welding stainless steel, 80 feet up in a manlift, in the middle of the night- the only time they would let us close the street to get the crane and manlifts in.
But to start out with, the setup welder689 described will work fine, for a minimum of bucks.
Actually, you don't even need the power block. Just clip the stick electrode holder, onto the lug on the argon hose/cable. Up to the limit of your 135 unit, that will work fine, as long as you get a good bite on the lug before starting and are careful not to bump either into/onto ground.
In my experience, scratch-starting a TIG on stainless really doesn't contaminate the tip to any significant degree.
I've also welded aluminum with scratch-start using an old Miller Econo-Twin AC/DC stick machine. No high-frequency, no foot-pedal, etc.
I'm sure you know this trick...scratch-start on a chunk of copper and then move the arc onto the aluminum work piece...so as not to contaminate the aluminum by touching the tungsten to it.
You can get by without a cooler on the water cooled torches, just run tap water thru it. I have mine set up to run off the garden hose spigot, just let it drain out into the grass. If you have very hard water that could be a problem (lime build up). You also have to make sure it is completely drained if your shop gets below freezing.
With a 130 amp welder, no need to be concerned with water-cooled torches.
interesting reading, i have been considering a tig attachment but i know very little about tig welding or the correct setup thats needed. i have two machines that are compatable. first is a late 80's miller, millermatic mig with the optional spool gun for aluminum. second is an early 90's miller (bobcat?) 225G welder/generator ac/dc arc welder. i know both these machines can be used with a tig setup but is there one particular tig setup that can be used on both machines? the mig is the main welder used in the shop, an old lincoln buzz box takes care of whatever would come in that needs stick/arc welding and the welder/gen is used as our portable welder for field work. can buy an attachment for use in the shop on the mig that can also be switched over to the welder/gen for field work as well? my knowledge of these machines is vague even though i grew up around them. my grandfather taught me to weld when i was only 10 years old with the lincoln arc/stick welder. due to his failing health i went from an unpaid employee to owner in the past few months. guess im just looking for a few ways to maximize the shops potential. thanks in advance for any replies.
Mig welders are almost always Constant Voltage.
A tig power supply needs to be Constant Current.
These are two different designs of the welding circuit.
So its pretty unlikely you can tig weld with your millermatic.
The bobcat should work fine, though.
Just set it for DC, plug in a tig torch, with argon tank and regulator, and you can tig weld.
Actually you can tig weld just fine with a CV (Mig) power source. Though unless you have infinite power control which i doubt his MM has you will have limited heat control since it is a tapped machine.
You learn something every day- I always thought tig welding only worked with CC machines.
A tapped machine has a series of preset amperage settings- 1, 2, 3, 4 or 100amps, 120 amps, and so on.
Whereas an infinitely adjustable machine has a knob that you can turn and get any spot in between. My CC/CV Miller inverter has a digital display, and you can dial it in one amp at a jump.
Handy for thin stuff, not so necessary for most purposes, but nice just the same.
This is the welder I want to use as a power supply
Infinitely variable up to 130 amps welder weighs 80 lbs
You might have a hard time clamping that rod holder to a power block.
El Cheapo half-assed solution...remove the rod holder (stinger) and vise grip the end of the cable to the power block...
or get a regular rod holder that you can clamp onto the power block.
El Cheapo half-assed solution...remove the rod holder (stinger) and vise grip the end of the cable to the power block---------------------
-I intend to use new cables and torch I will make power block as I have never seen them for sale in the UK
or you could cut the cable and splice in a lenco or dins type connector, that way you could swap back and forth between stick and tig.
how about putting a crimp terminal on a 6 inch tail of # 1/0 or 2/0 bare copper wire ( metricise for the UK) and clamp the stinger onto this like a big fat rod, bolt the terminal to the tig lead, off ya go ( bobs-yer-uncle @ US). wrap it with some electric tape if you are shy about grounding it accidentally but if it gets hot the tape will toast and come off, heatshrink tube might do better. CV and CC welding supply vs process is not as critical on ALL processes but is critical on some. you have to modify techniques and you have limited applications when you are working off the recommended type supply vs process but you can successfully do a good bit with it that way.
The cables on welder are bayonet fitting and only take a couple of seconds to remove likewise to replace with tig gun but I dont want to go to the expence of buying fittings if the welder shown in earlier post is not suitable.
"The cables on welder are bayonet fitting and only take a couple of seconds to remove likewise to replace with tig gun but I dont want to go to the expence of buying fittings if the welder shown in earlier post is not suitable."
Suitable for what?
What you will have will be the most basic of DC-only TIG set-ups.
You won't have any of the "fine tuning" capabilities of a top-of-the-line TIG machine, nor the amperage.
You will be able to do occasional TIG jobs on lighter duty steel and stainless projects or minor repairs.
If you need more than that, you can always upgrade later and the stuff that you've acquired (torch, regulator, hoses, etc.) can still be used on your next machine.
Personally, what you would have WOULD NOT satisfy my requirements for a TIG outfit...but you WOULD be able to do some TIG welding on a small scale.